Automatic slack adjuster



June 7, 1932. p B, CAMP AUTOMATIC SLACK ADJUSTER 3 Sheets-Sheet I l 1 Filed April 24, 1951 Z9 2 IIHHHin "m. "Hm

June 7, 1932. p, CAMP 1,862,136

AUTOMATIC SLACK ADJUSTER Filed April 24, 1951 5 Sheets-Sheet 2 Patented June 7, 1932 UNH'TE stares j PERCY B. CAMP, OF MAYWOOD, ILLINOIS, ASSIGNO R T UNIVERSAL DRAFT GEAR AT- TACI'IMENT COMPANY, A CORPORATION OF ILLINOIS AUTOMATIC SLACK aDJUs'rER Application filed April 24,

in which Fig. 1 is a plan view of the adjuster installed on freight equipment, the truck brake riggingat each end of the car being shown diagrammatically;

Fig. 2 is a transverse, sectional view taken on the line 22 of Fig. 1; I

Fig. 3 is a side elevational view of the actuating mechanism;

Fig. 4 is an'enlarged detail section of the rocker arm'and actuating rod taken on the line 4-4 ofFig. 2, the parts being shown in the position they assume when the piston travel has exceeded its normal distance;

Fig. 5 is a perspective view of the collar which fits over the push rod and 'actuates the rock shaft upon excess piston travel;

Fig. 6 is a plan view of the adjuster with a portion of the casing broken away to ex pose the interior;

Fig. 7 is a longitudinal, sectional view with the parts resting in their normal position;

Figs. 8, 9, and 11 are transverse, sectiona1 views through the adjuster taken on the lines 88, 99, 10-10, and 1111, respectively, in Fig. 7;

Fig. 12 is aview corresponding to Fig. 7 but showing the rack being extended from the casing preliminary to shifting the fulcrum of the dead lever; and

Fig. 13 is a composite view of the adjuster showing the various parts in perspective.

But this specific illustration and the correspondingly specific description are for the purpose of disclosure only for it is realized that various changes and modifications can be made in the structure shown in the drawings without departing from the spirit of this invention.

1931. Serial No. 532,573.

Itis characteristic of most brake'eq ment for freight cars that the dead cylinder lever is fulcrumed on the opposite side of the car from the air cylinder. This arrangement has been chosen to illustrate a particular adaptation of the present invention.

In Fig. 1, there is shown a pair of center car sills and 21 beneath which are suspended the various links and levers of the foundation brake gear. The live cylinder lever 22 and the dead cylinder lever 23 have connected to their respective working ends the usual top rods 24 which draw on the live truck levers 25 and push on the dead truck levers 26 through the intermediate bottom connecting rods 27 to apply the brake shoes 28 to the wheels 29. A center rod 30 connects the two cylinder levers in the usual manner. I j

The adjuster is rigidly secured to the bottom flange of the car sill 20, as shown in Fig. 2, and is braced by a truss 31 riveted to the web of the sill. I Y

The adjuster in its general organization comprises a casing A, a fulcrum block B,

an adjuster rack .C, a crank release 'arm D, a release handle E, and an oscillating arm F.

The casing A comprlses an elongated casting having a flat end wall 32,"lower side walls and 34, upper side walls 35, and 36, top

wall 37, intermediate top walls 38 and 39.

uip- I The lower side walls are carried inwardly at r 40 and then outwardly at 41 to form a seat for the wing-shaped fulcrum block.

Forwardly; facing rack teeth 42 are integrally cast with the internalinclined walls 40, the wall 32 being considered the forward end of the adjuster for convenience. rack teeth 42 extend the full length of the casing except for a small distance at the rear of the casingwhere the side walls 33 and 34' extend downwardly the full depth. of the casing. i H z The topof the casinghas an enlargement .43 to accommodate the release arm and the rear end of the casing-is provided with a protruding snout 44 which houses the takeup spring45. 'Preferably the upper wall of The 7 forces actlng on end of the rack.

clined face 61 of the The casing is provided with a suitable flange 47 for its attachment to the car sill, and preferably this flange is cast integrally as an extension of the intermediate top wall 38.

The fulcrum block B is intended to anchor the fulcrum of the dead cylinder lever at its proper position with respect to the car body so that normal brake shoe clearance will be constantly maintained. The block is provided with a jaw 48 receiving one end of the dead cylinder lever 23 which is held in place by a pin 49. Or linarily thepin is driven in from the bottom and a cotter 50 passing through the lower jaw arm prevents accidental dislodgement.

The fulcrum block is provided with inclined wings 51 which have integrally cast rearwardly facing rack teeth 52 on one end of their lower side which cooperate-'withthe rack teeth of the casing to anchor the ful crum block against movement to the right.

A rearwardly facing rack tooth 53 bridges the channel 54 between the wings 51 and coacts' with the adjuster rack to move the fulcrum block to the left when excess slack exists in'the brake system. 7

There is a normal tendency for the rear end of the fulcrum' block to rise upon application "of the brakes since the stress acting on the pin 49 is not in alignment with the reacting stress between the casingandfulcrum block teeth. To counteract this tend ency and in addition to useit to advantage, laterally extending lugs 55 are provided on the block which engage the walls 41 of the casing so that as the brakes are applied,-the

the block act as a lever to maintain the casing and fulcrum block teeth in engagement.

, The adjuster rack C rides upon the'fulcrum block and is held in constant engage ment therewith by the inclined take up spring 45. The rear end of the rack is channel-shaped as best shown in Fig. 8 and ter- Inmates in a aw 56 which recelves the oscillating arm F that operates the mechanism.

, The mid section of the rack has an elongated slot 57, the upper and forward walls of which are reinforced by a rib 58 which joins with an uprightendwall 59 at the forward The rack teeth 60 are cut into the lower face of the member and face forward. .7 d The talre-up spring 45 adjusted rack and is guided by a stud 62 extending from the rack in the direction of the casing'snout 44. For convenience of manufacture, this stud, 62 is preferably made separate from the adjuster rack.

In adjusters of this type, it is necessary to provide manual means for releasing the ful crum block so that new brake shoes may be substituted for those badly worn. In the presentcase, this is accomplished by acrank abuts against an in arm 63 pivoted at 64 in the casing and having a stud or lug 65 which rides in the slot 57.

The crank arm is operated by a handle 66 extending outsideof the casing and normally the adjuster rack.

In addition, this lug prevents the take-up v spring from dropping the forward end of the rack to such an extent that there is a possibilthus forms a support for the forward end of ity of therack'becoming disengaged with the fulcrum block.

;After the various'parts have been assembled withinthe casing, a spacer 68 is'bolted inplace'between the side walls 33' and 34 at the rear of the casing and furnishes a bearingi support for the rear end of the adjuster rac r.

The adjuster is operated directly from the push rod 69 of the air brake cylinder 70 through the intermediary of an actuating rod 71 and a rock shaft 72. A lost motion is provided between the actuating rod and the rock shaft so that the latter is oscillated only upon excessive piston travel. j

The push rod 69 carries a collar,73'having spaced side walls 74 which are apertured at 7 5 to receive a lever pin 76. The collar is reinforced by a rib 77 merging into a drilled'he'ad 78 which is slightly offset as shown in Fig. 3 1

to avoid interference, between the actuating rod and the livecylinder lever. 1 I

Theactuating rod 71 is adjustably secured in the head 78 of the collar by nuts 79. The

other end of the rod carries a stop-member 8O substantially'square in cross section and provided with an upstanding lug 81on its upper face. I r

The rock shaft 72 is rotatably-mounted beneath the car body and passes through the webs of the car. sills 20 and 21. At one end of the shaft is a rocker arm generally designated 1 3 82 which cooperates with the actuating rod 71 82 has integral depending legs 85 and 86 join ing with each other at 8710 form a trough for the, actuating rod. 'Preferably, the trough is peaked asv at 88 for a purpose to be later jdescribed. A strap 89 connects the mid section of the two legs. 1 V 1 A latch 90 is pivoted at-j9l between the legs 85 and'86 of the rocker arm and is of length that it forms an obstruction for the lug 81 when the actuating rod 'Zlmoves a distance greater than normal piston travel. As

section, and is held in place The sleeve portion of the such the lug 81 strikes the toe 92 of the latch, it rotates'the rock shaft in a counterclockwise direction, since the strap 89 prevents independent counterclockwise movement of the latch. 11 emergency application of the brakes 'where the piston travel may be two or three inches in excess of its travel under normal conditions, the latch 90 will permit the lug 81 to pass beneath it after the rocker arm has been rotated a predetermined amount. Upon release of the brakes, the lug will swing the latch in a clockwise direction, there being no obstruction, and the parts will resume their normal position.

It will be seen that the peak 88 of the trough 87 slightly raises the actuating rod during the crucial movement of the rod 71 and then lowers it with respect to the pawl 90 when the excess piston'travel is more than the desired take-up of the adjuster.

The adjuster end of the rockshaft is equipped with a hooked arm having'an exterior bearing surface 93 journaled in a hearing 94 on the casing extension 95. The de pending hook 96 engages the cross pin 97 of the jaw 56 of the adjuster rack and operates the device.

The rocker arm latch 90 and the lug 81 of the actuating rod are so proportioned that the maximum'rocking of the shaft 72 will produce a linear displacement of the adjuster rack sufficient to take up one tooth of slack but no more. The proportions may, of course, be varied so that any other number of teeth may be taken up on a single application of the brakes. Upon release of the brakes or after the lug 81 has slipped beneath the toe of the latch in case there has been an emergency application of the brakes, the spring 45 will return the rack to its normal 'posi tion carrying the fulcrum block with it. The tooth 53 of the fulcrum block will then be found engaging the rack tooth immediately forward of the one it was'engaging before the brakes were applied. The new position of the fulcrum block is maintained by the correspondingly new engagement between the fulcrum block teeth 52 and the casing teeth 42.

It will be noticed that the fulcrum block is anchored against movement'to the right so that upon brake application, the dead lever fulcrum will be fixed. In addition,

the casing fulcrum block teeth prevent the fulcrum block from being moved to the right when the adjuster rack is actuated by excess brake travel.

To release the adjuster for the insertion of new brake shoes, it is only necessary to lift the release handle 66 whereupon the fulcrum block may be raised from .the casing teeth and moved back to the right.

What I claim, therefore, is:

1., In a brake system for railway cars including a live cylinder lever receiving power at one end from a brake cylinder push rod and a dead cylinder lever diagonally fulcrumed with respect to said end to the underframe of the car, the combination of meansto adjust said dead cylinder lever-fulcrum to regulate the system comprising a support for the dead cylinder lever fulcrum, and means for selectively anchoring the said lever fulcrum to the support, said last named means including a rock shaft, an actuating rod moving with the brake'cylinder push rod, and a rocker arm on the shaft provided with a lost motion connection with the actuating rod.

2. In a brake system for railway cars including a. live cylinder lever receiving power at one end from a brake cylinder push rod and a dead cylinder lever diagonally fulcrumed with respect to said end to the underframe ofthe car, the combination of means to adjust said dead cylinder lever fulcrum to regu late the system comprising a support for the dead cylinder lever fulcrum, and means for selectively anchoring the said lever fulcrum to the support, said last named means including a rock shaft, an actuating rod m0ving with the brake cylinder push rod, a rocker arm on the shaft provided with a lost motion connection with theactuating rod, and means 7 for limiting the ad ustment during any one application of the brakes. 1

3. In a brake system for railway cars including a live cylinder lever receivingpower. at one end from a'brake'cylinder push rod and a dead cylinder lever diagonally-fulcrumed with respect to said end to the under frame of the car, the combination of meansto adjust said dead cylinder lever fulcrum to regulate the system comprising a support for the dead cylinder" lever fulcrum, and means for selectively anchoring the said lever fulcrum,- to the support, said last named means including a rock shaft transversely mounted beneath the car, an actuating rod operatively connected to the brake cylinder push rod and moving with and parallel there to, at least during excessive piston travel, and a rocker arm on the shaft associated with the actuating rod and adapted to rotate the shaft only upon excess piston travel. a

4. In a brake system for railway cars including a live cylinder lever receiving power at one end from a brake cylinder push rod and a dead cylinder lever diagonally fulcrumed with respect to said end to the underframe of the car, the'combination of means to adjust said deadcylinder lever fulcrum to regulate the system, comprising support for the dead cylinder lever fulcrum, and means for selectively anchoring the said lever fulcrum to the support, said last named means including a rock shaft transversely mounted beneath the car, as actuating rod moving with the brake cylinder push rod and parallel thereto, a rocker arm on the shaft travel and a latch device for limitingthe amount of adjustment on any one application of the brakes.

' 5. In a brake mechanism of the type including a live cylinder lever, a .dead cylinder lever, and an air cylinder having a push rod operating on the live cylinder lever, the combination of means for adjusting the fulcrum of the dead cylinder lever comprising a fixed casing provided with internal rack teeth a fulcrum block supporting the fulcrum of the dead cylinder lever and adjustable along the casing, an adjuster shiftablewith relation to the fulcrum block upon excess brake travel, spring means for restoring the adjuster to normal position and moving the fulcrum block to adjusted position upon release of the brakes, and actuating mfechanism associated with the adjuster, said actuating mechanism including a rod moving with the air cylinder push rod, a rock shaft adapted to be oscillated when the rod is moved a distance in excess of normal piston travel, and an arm mounted on the shaft operatively connected with the adjuster to effect the adjustment. 4 6. In a brake. mechanism of the type includinga live cyl'nder levcr, a dead cylinder lever, and an air cylinder having a push rod tion upon release of mechanism including a rock shaft operativeoperating on'the live cylinder lever, the combination ofmeans for adjusting thefulcrum of the dead cylinder lever comprising casing having internal forwardly facing rack teeth, an adjuster rack within the casing movable only upon excess piston travel, a fulcrum block pivoted tothe fulcrum of the dead cylinder lever, rearwardly facing rack teeth 7 oh the block coo crating with the casing teeth a to hold the dear/cylinder lever fulcrum im2- movable during brake application, a rear;- wardly facing tooth on the blockengaging the adjuster rack, spring means operating to return the adjuster to its normal position and the fulcrum block to its adjusted posithe brakes, and actuating ly connected with the air cylinder push rod.

.7.In a

V, combination of means brake'mechanism of the typeincluding a live cylinder lever,'a dead cylinder'lever, and an air cylinder having a push thelive cylinder lever, the for adjusting the dead cylinder lever fulcrum. comprising asupport fixed to the underframe of a car body,

rod operating on -v two members freely movable with respect to each other in one direction but held against relative movement in the other direction, one of the members supporting the fulcrum of the dead cylinder lever, actuating mechanism,

connected to the other member adapted to produce relative movement only upon excess piston travel, said mechanism including a rock shaft and an inclined spring urging the two members into constant engagement and J adapted tooreturn the one member to normal a fixed position andmove theother member to ad justed position upon release of the brakes. V

'8. In a brake mechanism of the type including a live cylinder lever, a dead cylinder lever, and anair cylinder having a push rod operating on bination of means for adjusting, the dead cylinder lever fulcrum comprisinga support fixedto the, underframe of a car body, two members freely movable with respect to each other in one direction but held against relative movement in the other direction, one of the members supporting the fulcrum of the dead cylinder lever, actuating mechanism connected to the other member adapted to produce relative movement only upon excess piston travel, said mechanism including a rock shaft and means for limiting the amount of adjustment during-any one application of the brakes, and aninclined spring urging the two members nto constant engagement and the one member to normal positionand move the other member to adjusted'position upon release of the brakes.

9. In a brake mechanism of the type in adapted to return cluding a live cylinder lever, a. dead cylinder lever, and an air cylinder having a push rod operating on the livecylinder lever, the combination of means for adjusting the fulcrum of the dead cylinder lever comprising a fixed the live cylinder lever, the com-' casing provided with internal rack teetl1,.a fulcrum block supporting the fulcrum of the dead cylinder lever and adjustable along the casing, an adjuster shiftable with relation to the fulcrum block upon excess brake travel,

spring means for restoring the adjuster to normal position andmoving the fulcrum 

